This invention concerns improvements in or relating to milking apparatus, in particular, the invention is concerned with improvements in or relating to inflations, used in milking machine claw assemblies, which attach to the udder of a cow.
Those skilled in the art will appreciate that a milking machine teat cup claw assembly is composed of four teat cup assemblies, connected via a "claw" to a pulsing mechanism and to the vacuum milk flow line of a milking machine.
A teat assembly is made up a rigid outer teat cup having two open ends in which is positioned a inflation, the inflation usually being made from synthetic rubber.
For the efficient milking of a cow, without risking damage to the teat or udder, the inflation must flex smoothly, and in the manner in which it has been designed. In this way the milking operation is able to extract the maximum amount of milk from the cow without distressing the animal.
The inflations are consumable items, in that they require replacement at regular intervals of time. In some areas, replacement each year is required, and in others, more frequent replacement occurs. If undue wear occurs on the inflation or other deleterious factors apply, then replacement at shorter than usual intervals of time becomes necessary.
Because the inflation must seal against the teat cup at both ends, referred to as the bottom and the top ends, of the cup, to allow the pulsed vacuum applied to the cup of change the shape of the inflation, it is, by necessity, a tight fit at each end of the cup. Removal and replacement of inflations in teat cups, or, installation of inflations in the first instance, requires some effort and produces difficulties in many cases.
It is not uncommon in using milking machine apparatus to find that one or more of the four teat cup assemblies in a claw assembly does not milk satisfactorily. That is to say, it does not extract milk efficiently from the animal being milked. It has been found that this is often attributable to incorrect fitting of the inflation in the cup, due to the difficulties mentioned above, or, the lack of care shown when inserting the inflation into the cup at installation or replacement.
It has been found that what happens is the end of the inflation at the top of the teat cup is twisted radially with respect to that part of the inflation at the bottom end of the teat cup. It is believed that this occurs in the final positioning of the inflation into a sealing contact with the ends of the teat cup. The torsional resilience of the inflation is not sufficient to unwind the radial twisting, once the inflation is fully fitted in the cup. As a result, the milking operation is conducted with the inflation operating with a twist, causing it not to expand and contract as designed, or as desired, for efficient milking. It is believed that premature wearing of the inflation may also occur when it is operated in that condition.
This problem is difficult to identify where the cup itself is not transparent, which is the usual one. This is because it is not possible to inspect the inflation within the cup, once it has been inserted. While a number of solutions to the problem of twisted inflation have been proposed, these suggested solutions are ineffective when inflations are replaced under poor light, or in the dark, as may be the case in milking sheds. In an event, these attempts to solve the problem still rely entirely upon the operator separately checking the alignment of each end of the inflation after it has been inserted in the cup.